Pump structure



Jan. 12, 1954 E. J. SVENSON 2,665,639

PUMP STRUCTURE Original Filed May 3, 1939 4 Sheets-Sheet 1 INVENTOR Jive/2.50m BY: M /7/L%J Jan. 12, 1954 E. J. SVENSON PUMP STRUCTURE 4 Sheets-Sheet 2 Original Filed May 3, 1939 INVENTOR. rrzes'fffibemiam Jan. 12, 1954 E. .1. SVENSQN PUMP STRUCTURE Original Filed May 5, 1959 4 Shuts-Sheet :5

I76 a 33 go 144 9 I i 142 j) v Jan. 12, 1954 E. J. SVENSON PUMP STRUCTURE Original Filed May 3, 1939 4 Sheets-Sheet 4 I INVENTOR. fi West f Jazz /(5107a Www Patented Jan. 12, 1954 PUMP STRUCTURE Ernest J. Svenson, Rockford, Ill., assignor to Odin Corporation, Chicago, 111., a corporation of Illinois Original application May 3, 1939, Serial No.

271,444. Divided and this application November 7, 1946, Serial No. 708,340

7 Claims. 1

This invention relates to pump structures, and more particularly to pump Structures of the reversible type adapted for propelling fluid to and receiving fluid from an actuated device, and wherein the fluid requirements of the actuated device are diiierent in its opposite directions of travel.

It is an object of the invention to provide a pump structure of the foregoing type, of improved construction and improved operating characteristics.

More specifically stated, it is an object of the present invention to provide an improved pump structure, such as a rotary gear pump or the like, which incorporates improved means for compensating the pump delivery, both to make up fluid deficiency and to dissipate fluid excess, as for example in installations wherein a differential exists in the volumetric delivery of fluid to and from the pump in normal operation.

A still further object of the invention is to provide an improved reversible gear pump, and compensating means therefor.

This application is a division of my prior copending application, Serial No. 271,444, filed May 3, 1939, and entitled Hydraulic Actuator Mechanism, now abandoned in favor of my application, Serial No. 708,339, filed November 7, 1946, as a continuation-in-part of the earlier application, and of which the present application also constitutes a division. The present application concerns particularly the pump structure disclosed in said prior cases.

Various other objects, advantages and features of the invention other than those hereinbefore specifically referred to, will appear from. the following specification when taken in connec tion with the accompanying drawings wherein certain preferred embodiments of the invention are illustrated.

In the drawings, wherein like reference numerals refer to like parts throughout:

Fig. 1 is a general assembly view, somewhat diagrammatic in form, of a printing press shift,- abie roller installation incorporating pump structures constructed in accordance with and embodying the principles of the invention;

Fig. 2 is a View on an enlarged scale of the hydraulic actuator structures, and associated parts, as embodied in the structure shown in Fig. 1;

Fig. 3 is a detail sectional view of the pump structure and associated parts, in the installation of Figs. 1 and 2, taken as indicated by the line 3-3 of Fig. 2;

Fig. 4 is a sectional view through the pump and associated actuator cylinder, taken on the line 4-4 of Fig. 3;

Figs. 5, 6 and 7 are sectional views of a modified form of pump structure, Figs. 61 and 7 being taken on the lines 66 and 1-4, respectively, of Fig. 5;

Fig. 8 illustrates a further representative installation incorporating pump structures constructed in accordance with the invention, the installation shown being one for effecting the hydraulic shifting of valves; and

Fig. 9 and 10 are sectional detail views, on an enlarged scale, of the valve actuator structures, and associated parts, as shown in Fig. 8, and taken on the lines 9-9 and Ill-l0, respectively, thereof.

In many installations which are adapted for pump actuation, the requirements of the system are such that a diiierential exists between the volume of fluid to be propelled from and delivered to the pump during its actuation. For example, in instances wherein a gear pump is interconnected with a reciprocable hydraulic actuator in a closed circuit, if the actuator has a piston rod projecting from only one end thereof, as is frequently the case, a differential will exist between the volume of fluid which must be deliver-ed to the actuator to enect the propulsion of the actuator piston, and the volume of fluid which is returned from the actuator to the pump, from the return side of the piston. If the pump is reversible, and thus arranged to propel the actuator piston in opposite directions of travel,

an excess of fluid will be returned to the inlet side of the pump during actuation of the actuator piston in one direction of travel, whereas there will be a deficiency in the amount of fluid returned to the inlet side of the pump when the actuator piston is propelled in its opposite di rection of travel.

In accordance with the present invention an improved pump structure is provided, having im proved features and characteristics, and including improved means for compensating the fluid delivery of the pump in accordance with the foregoing requirements.

In Figs. 1-7 of the drawings, an embodiment of the invention is illustrated wherein pump propelled hydraulic actuator mechanisms are utilized for shifting printing press rollers, whereas in Figs. 8-40 the pump structure of the invention is shown as applied to the shifting of valves or the like. It is to be understood, however, that the pump of the invention, and the various characteristic-s thereof, are adapted for use in a wide variety of installations, including installations for effecting the hydraulic propulsion of various machine parts.

Referring more particularly to the drawings, and first to the structures illustrated in Figs. 1-4, in Figs. 1 and 2 there is illustrated a printing press or paper handling machine incorporating three units I2, i4 and I8, each of which is provided with a hydraulic actuator structure for shifting the paper handling rolls.

As shown in Fig. 2, each unit includes a reversible electric motor I8 adapted to drive a gear pump 29 mounted within a liquid reservoir 22. As will presently appear, the intake and exhaust passages of the pump are hydraulically connected to a reversible hydraulic actuator 24 which through suitable mechanical linkage shifts the roller or blanket cylinder 26 upwardly out of engagement with the pressure cylinder 33', or downwardly into engagement with said pressure cylinder and the associated paper supporting web 3| as the occasion may require, to effect the printing operation.

Referring more specifically to the hydraulic actuator structure shown, it will be seen that a housing 535 integral with a support plate 95 mounted on the frame bracket 32 supports the actuator cylinder 36, Fig. 3, cast integrally with the outer housing member 92 of the pump 20. A piston 30, Fig. l, carried by a piston rod it operates within the cylinder, there being end plates or covers 42 with the usual sealing means or gasket 44 and piston rod packing means 4%, for preventing fluid leakage from the cylinder along the piston rod.

The piston rod 40 carries at its outer or upper end a yoke member 48 mechanically interconnected with the linkage previously mentioned, for effecting the desired shifting operations.

Motor i8, which may be of any suitable reversible type, is connected to the pump 20 by any suitable or conventional coupling 86, Figs. 2 and 3, interposed between and secured to the motor shaft 83 and the actuating shaft 90 of the pump 20. The pump 20 comprises a housing member 02 formed integrally with the cylinder 3%, and a cover plate 04, the pump 20 projecting into and being mounted upon the housing 95 forming the oil reservoir 22. The oil reservoir housing is formed integrally with the support plate 95 for the motor I8.

The pump drive shaft 90 is journaled in bushings Q8 and is provided with a suitable liquid seal I preventing leakage of the liquid along the shaft. A drive gear I02 is cut integrally with the shaft so and meshes with a companion pump gear I04 secured to a rotatable sleeve I03 iournaled on a normally stationary but adjustable pin or stud shaft I08 held in position by its shoulder 5 I0 and a cap screw H2. The pump gear I34 is provided with a set of angularly spaced radial passages H4 communicating with similar radial passages H6 in the sleeve E06, the passages I It being adapted to communicate in sequence with slots or chambers H8 and H9 formed in the shaft I08. Liquid trapped between the teeth of the gears at the meshing position is relieved by the passages H4, I I6 and the chambers H3 and M9, the chamber H3 being operative when it is on the outlet or discharge side of the pump as the pump is operating in one direction, and the chamber IE2 being operative when it is on the discharge side as the pump is operating in the reverse diree i mi Th chambers relieve the liquid trapped between the teeth of the gears, preventing crushing thereof by allowing it to be relieved back into the exhaust chamber. If desired, the sides of the teeth of the gear I04 may be radially grooved to provide additional relief passages as will be more particularly pointed out hereinafter in reference to the embodiment of the invention shown in Figs. 5, 6 and 7. Also, shaft we may be adjusted rotatably to permit the return of liquid from the high to the low pressure side of the pump through the chambers H8 or MS in regulatable amounts as determined by the adjustment of the shaft. See, for example, Svenson Patents Nos. 1,912,737 and 1,912,738, dated June 6, 1933.

The chamber containing the pump gears I532 and I04 is connected to the actuator cylinder 35 by liquid supplying and discharging ports 12% and I22, the port I20 constituting the inlet and the port I22 the outlet when the pump gears are driven in one direction, and the port I22 constituting the inlet and the port I26 the outlet when the pump gears are driven in the opposite direction. The port I255 extends into communication with the cylinder 35 above the piston as seen in Fig. i, and the port its extends into communication with the cylinder below the piston.

It will be apparent that in a closed hydraulic system or circuit, such as disclosed, wherein the piston rod 40 occupies a portion of the cylinder on one side only of the piston, there exists a difference in the volume of liquid displaced on opposite sides of the piston per unit of piston movement. In order to compensate for this difference in volume there are provided two compensating channels or passages I24 and I26 extending through the pump housing member 92 radially with respect to the pump gears and from the pumping chamber into communication with the reservoir 22. When the pump gear I02 is driven in a counterclockwise direction as seen in Fig. 4, liquid is supplied to the pump chamber through the port I20 from the chamber IZii above the piston 38 and forced, under pressure, through the port I22 into the chamber I30 below the piston 38. As the piston 38 moves upwardly or outwardly, less liquid is displaced per unit of movement than is required to fill the space created below the piston by the same unit movement. Therefore, it may be stated that less liquid is available to the inlet port I 20 of the pump from the chamber I28 above the piston than must be supplied through the outlet port I22 of the pump to the chamber I30 to move the piston 38 upwardly. As the piston 38 moves upwardly, a slight vacuum is thereby created in the inlet port I20 due to this difference in the volume of the displaced liquid on opposite sides of the piston and accordingly when each partially filled space between an adjacent pair of teeth of the pump gears I04 and I02 registers with the increasing compensating ports or passages I24 and I26, additional liquid sufiicient to fill these spaces is supplied from the reservoir through these ports I24 and I 26.

When the pump drive gear I02 is rotated in the clockwise direction, as seen in Fig. 4, more liquid is available to the inlet port I22 of the pump per unit of movement of the piston than can be accommodated by the chamber I28 abovethe piston. This surplus liquid creates a slight pressure in the inlet port I22 and is relieved by liquid passage through the ports I24 and I26 into the reservoir 22 as the spaces between ad- 5 j'acent teeth on the pump gears register with the ports I24, I26.

It will be evident from the description of the form of the invention illustrated in Figs. 1 to 4, that applicant has provided a very simple and efficient pump structure for propelling a machine part, a printing press cylinder in the specific embodiment illustrated, and that by reversal of the driving motor, the direction of movement of such a machine part may be readily controlled without the use of any additional valve mechanisms.

For installations wherein there is a still greater difference in the volume of liquid displaced on opposite sides of a piston per unit of movement, the invention provides the modification illustrated in Figs. 5 to '7. In this form of the invention the pump gear I64 is provided with two axially spaced sets of radial passages II4 leading inwardly from the spaces between the gear teeth, and is secured on the rotatable sleeve I66 provided with similar sets of radial passages I I 6 communicating with passage I I4, the sleeve I66 being rotatably journaled on a second fixed sleeve I36. The teeth of the gear I64 may also be provided on one side with radial slots I I5 axially positioned between the sets of passages I I4.

The sleeve I36 is secured to the pump housing member 92 and the cover 64 by a flange I31 formed on one end of the sleeve and a threaded plug I38 secured to the other end thereof. second threaded plug I36 seals the flanged end of the sleeve. The sleeve I36 is provided with peripheral chambers or slots I46 and I42 generally similar to the chambers H6 and H6, previously described, except that they are axially as well as angularly Spaced. The slots I46 and I42 communicate through the sets of radial passages I I6 and I I4 of the sleeve I66 and the gear I64 with the pump chambers I46 and I44. A shiftablevalve member I48 is included as a part of the pump and .is slidably mounted within the sleeve I36 for movement between the threaded plugs I36 and I36, and this member is provided with a plurality of valve heads I56, I52 and I 54. The valve head I52 selectively controls communication between radial ports I56 and I53 in the sleeve I36 and the interior chambers I66 and I64 of the sleeve I36, the ports I56 and I56 registering with the peripheral chambers or slots I42 and I46 in said sleeve. are in constant communication with the main reservoir 22 by means of passages I62 and I66. The valve head I56 seals the chamber I66 and the valve head I54 seals the chamber I64. Liquid for shifting the valve member I48 is supplied to the interior of the sleeve I36 on the outer sides of the valve heads I56 and I54 by means of ports or passages I68 and I16 which are connected to the ports or passages I14 and I12 through which liquid passes to and from the chambers I13 and I16 of a cylinder I66, to and from the pump chamber I46 and I44. The cylinder I86 corresponds to cylinder 36 of Figure 4 and has mounted therein a translatably shiftable piston I62. The cylinder I66 and piston I62 of Figure 6 perform the same functions as do the cylinder 36 and piston 36 of Figure 4.

As the pump driving gear I62 rotates in a counterclockwise direction, as seen in Fig. 6, liquid is withdrawn from the cylinder chamber I18 on the piston rod side of the piston I32 through the port I14 into the pump chamber I46 and supplied under pressure from the pump chamber I44 to the cylinder chamber I16 through the port I12, causing piston I82 to move to the right as Chambers I66 and I64 seen in Fig. 6. The pressure of the liquidin the port I16 which is in communication with the exhaust pump chamber I44, being greater than the pressure of the liquid in the port I68 which is in communication with the inlet pump chamber I46, the valve member I48 is moved to the left to the position shown in Fig. 5. As the piston I82 moves to the right, there is less liquid available in the cylinder chamber I18 per unit of movement of the piston than is required for the cylinder chamber I16. This deficiency of liquid is compensated for by the drawing of the required liquid into the inlet pump chamber I46 from the main reservoir 22. This liquid is drawn from the reservoir through passageway I66, chamber I64, passageway I58 which is now open because the valve member I46 is in the position of Figure 5, slot I46 and passageways H6 and I I4 into the inlet pump chamber 546.

When the pump driving gear I62 is rotated in the opposite direction to effect movement of the piston I82 to the left, as seen in Fig. 6, liquid is withdrawn from the cylinder chamber I16 into the pump chamber I44 through the port I12 and is supplied under pressure to the cylinder chamber I16 from the pump chamber I45 through the port I14. Pump chamber I46 now being on the exhaust or pressure side of the pump, pressure is transmitted through the passageway I56 to act onthe valve head I56 and cause the shifting of valve member I48 to the right, away from the position shown in Fig. 5, opening the passageway I56 and closing the passageway I56 by the shifting of the valve head I52. As the actuator piston I62 now moves to the left, the volume of liquid displaced by the piston from the cylinder chamber I16 is greater than that required for the cylinder chamber I18 per unit of piston movement. Passageway I56 now being open, this excess liquid is lay-passed from the pump chamber I44 through radial passageways H6 and H6, slot I42, passageway I56, chamber I56, and passageway I62 into the main liquid reservoir.

It will be seen that due to the shiftable valve member I48 the passageways I56 and I56 are closed when on the high pressure side or" the pump and open when on the low pressure side thereof to compensate for liquid excess or deficiency. Compensation is made for the dinerences in volume on the two sides of the actuator piston I82 without any loss of pressure on the pressure side of the pump.

The slots or chambers I46 and I42 not only cooperate with passages I56 and I56 to compensate for liquid excess or deficiency, in the manner stated, but they also act to prevent crushing of the fluid in the manner previously described with reference to chambers H8 and I56 in Figures 1-4. The radial passageways H4 and IE5 cooperate with the chambers to prevent crushing of the liquid at the base of the teeth of the gear I64, and the radial slots H5 in effect communicate with passages I I4 and I I6 to prevent crushr ing of the fluid at the base of the teeth in the gear I62. The chambers I46 and I42 remain operative to prevent fluid crushing even when the associated passageways I53 and I56 are closed.

Suitable means, forming no part of the present invention, may be provided for initiating and controlling the forward and reverse operation of the motor or motors I8.

In Figs. 8, 9 and 10 a valve actuating installation is set forth as illustrative of a further instance of use of the present invention. As

shown, the installation set forth in Fig. 8 may, for example, comprise a part of the piping system of a gasoline or oil refining installation. In systems of this type the various valves in the installation must be opened and closed quickly, positively, and efiiciently, as may be effected by means of the pump structure of the present invention. Further, the arrangement is such that the valve actuating piston rod projects from the hydraulic actuator in but one direction, creating the problems of differential fluid delivery to and from the pump, as previously described.

Referring more specifically to Fig. 8, the piping system shown may comprise a main pipe line 536 and auxiliary pipe lines 55M and 5% through which various treating agents may be introduced into the main pipe line or through which liquid or fluid therein may be withdrawn. Valves 5B8, 5| 0, M2 and 514 are provided in the main pipe line to control the flow of fluid therethrough and to the various auxiliary pipes. These valves are provided with hydraulic actuating units Filfi, 5l8, 520 and 522, respectively.

Each of the valve structures and their associated hydraulic actuating units may be identical in construction. As shown in Figs. 9 and 10, each includes a valve rod 538, to the lower end of which the valve member of the unit is secured. The valve rod extends upwardly through the valve bonnet structure 532 which forms the support for the hydraulic actuating unit.

At its upper end the valve stem 539 is connected to the actuating piston rod 56:8 of the actuating unit, the valve stem also having connection with the actuating rod 555 of an electric motor control switch structure 553, forming no part of the present invention.

In addition to the piston rod 548, the actuator unit comprises a main cylinder casting 56S having two different size cylinder bores 563 and 5'56, the upper bore containing the piston 512 secured to the upper end of the piston rod 548, and the lower bore containing a floating piston 52%; the latter having a head portion 518 extending upwardly for engagement with the upper piston.

Each actuator unit further includes an electric motor 518, Fig. 10, a pump 5%, and a fluid reservoir 582. This pump structure may be of the type previously described in reference to Figs. 3 and 4, or of the type specifically described in reference to Figs. 5, 6 and '1. The main casting of the pump forms one wall of the oil reservoir 582, the other walls of which are formed by the housing The pump is mechanically connected to the motor 518 by means of a coupling 5%, as shown in Fig. 10.

The ports or passages 5% and 53 4 connect the inlet and outlet ports 5% and 598 of the pump to the upper end of the cylinder bore 538 and to the lower end of the cylinder bore 516, the ports or passages 592 and 59 5 being formed in the pump casting, and in the associated parts of the hydraulic actuator, eliminating the need for any outside piping. The fiuid passage or port Bull extends through the main cylinder casting 565 from the upper end of the cylinder bore 568 to the lower cylinder 519. The enlarged central bore 582 of the piston head 516 provide a fluid passage about the piston rod 558, permitting the fluid to pass from the under side of the piston 511 to the under side of the piston 512.

Assuming the valve structure to be closed, as shown in Fig. 9, upon operation of the pump in a direction to effect an upward movement of the piston rod 5 18, the pump withdraws fluid, which is preferably oil, from the cylinder bore 568 above the piston head 512 through the port 592 into the pump port 596 and forces fluid through the port 5&8 and the port 594 into the cylinder bore 510 below the piston 514. The power or floating piston 514 under. the force of the fluid moves freely for a predetermined distance determined by the space 594 until the upper end of the head portion 516 strikes the lower wall of the piston 512. Thereupon the piston 512 is propelled upwardly to effect the opening of the valve, the fluid being supplied thereto through the passage 662. The piston 514 moves only a predetermined selected distance until stopped by the upper wall of the cylinder bore 510.

Upon operation of the pump in the opposite direction, to effect the closing of the valve, fluid will be withdrawn from the cylinder chamber 563 beneath the piston 512 and from the cylinder chamber 519 beneath the piston 51 through the port 594 to the pump port 598, and forced under pressure through the pump port 596 and the port 592 into the cylinder chamber 563 above the piston 512. Fluid is also forced into the cylinder chamber 518 above the piston 5M from the cylinder chamber 588 through the port Gila. This operation forces both of the pistons 512 and 514 downwardly to effect the closing of the valve.

It will be seen that in this instance not only does the piston rod 548 project in a uni-directional manner from the hydraulic actuator, but two pistons of diiferent size and movable at different times are provided, the pump being interconnected therewith in a closed circuit. The diiferential in Oh delivery to and from the pump, under the various operating conditions, may be compensated by the means heretofore described either in reference to Figs. 3 and i, or in reference to Figs. 5, 6 and 7.

It is obvious that various changes may be made in the specific embodiments set forth without departing from the spirit of the invention. The invention is accordingly not to be limited to the embodiments shown and described, but only as indicated in the following claims.

The invention is hereby claimed as follows:

1. A reversible pump for pumping fluid to and from a source of variable capacity, said pump comprising a casing, a plurality of cooperating and relatively rotating fluid pressure generating members therein, inlet and exhaust passageways in the casing communicating with said members, auxiliary passage means providing a fluid path communicating through the casing with the path of rotation of at least one of said members in the pressure zone thereof, a fluid reservoir communicating with said auxiliary passage means, and means subjecting said auxiliary passage means to variations in fluid pressure in the path of rotation of the member with which the passage means communicates whereby to modify the fluid volumes exhausted from and delivered to said source by said members.

2. A reversible pump as claimed in claim 1, wherein the casing includes a pump chamber in which the fluid pressure generating members are disposed and with which the inlet and exhaust passageways communicate, and wherein the pressure zone of said fluid pressure generating member is defined by surfaces including the periphery thereof and the wall of said chamber.

3. A reversible pump as claimed in claim 1, including valve means for controlling the passage of fluid through said auxiliary passage means.

4. A reversible pump as claimed in claim 3,

wherein the auxiliary passage means includes a pair of passages and the valve means is shiftable to selectively control the flow of fluid through said passages.

5. A reversible pump as claimed in claim wherein the auxiliary passage means comprises a pair of passages on opposite sides of the casing and each communicating with the path of rotation of the periphery of a separate pressure generating member.

6. A reversible pump for pumping fluid to and from a source of variable capacity, said pump comprising a casing, a plurality of cooperating and relatively rotating fluid pressure generating members therein, inlet and exhaust passageways in said casing communicating with said members, a fixed sleeve mounted in said casing and on which one of said members is mounted, said sleeve having a valve chamber internally thereof, a pair of auxiliary passages including aperture means through said sleeve communicating through said valve chamber with the path of rotation of the periphery of at least one of said members, a fluid reservoir communicating with said auxiliary passages, a valve plunger mounted within said valve chamber and including valve means shiftable to selectively open one and close the other of said passages, and means effecting the shifting of said valve plunger and valve means in response to variations in fluid pressure in the inlet and exhaust passageways to open one and close the other of said auxiliary passages and subject the one to variations in fluid pressure in the path of rotation of the periphery of the communicant pressure generating member whereby to modify the fluid volumes exhausted from and delivered to said source by said members.

7. A reversible pump as claimed in claim 6, wherein one of said pressure generating members is provided with peripherally spaced ports successively communicating with said aperture means as the member rotates to afford communication between the aperture means and the pressure generating area of said members.

ERNEST J. SVENSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 788,848 Riegel May 2, 1905 1,103,053 Kiefer July 14, 1914 1,633,793 Porst June 28, 1927 1,728,529 Butler Sept. 17, 1929 1,742,215 Pigott Jan. 7, 1930 1,912,737 Svenson June 6, 1933 1,912,738 Svenson June 6, 1933 1,978,480 Svenson Oct. 30, 1934 2,029,742 Sieverts Feb. 4, 1936 2,079,375 McCollum May 4, 1937 2,149,326 Wilkin Mar. 7, 1939 2,157,285 Egersdorfer May 9, 1939 2,163,764 Rockwell June 27, 1939 2,263,548 Mueller Nov. 18, 1941 2,292,331 Vertson Aug. 4, 1942 2,382,701 Egersdorfer Aug. 14, 1945 2,497,247 Von Wangenheim Feb. 14, 1950 

